US2918973A - Perforation clean out tool - Google Patents

Description

Dec. 29, 1959 P. K. ozlNGA PERFORATION CLEAN OUT Toor.

Filed Oct, 16, 1953 I/ Il United States This invention relates to a tool whereby the perforated portion of the casing or the screen may be eifectively cleaned, that is, dirt or other material may be effectively washed out of the perforations through which an oil well is produced.

In tools of this type heretofore in use, it was impossible to establish circulation throughout the entire length of the perforated pipe or screen or of the annulus behind the screen or pipe.

Furthermore, these devices previously in use do not provide any means by which solids which have been obstructing the perforations in the pipe or screen can be removed from the annular space back of the screen or pipe without passing them through the same screen openings which are intended to be cleaned or washed and which must ultimately serve for production of the well.

An object of my invention, therefore, is to provide a novel perforation washing tool which will eifectively and properly wash and clean the outside of the screen as well as the perforations in that screen.

A further object of my invention is to provide a novel washing tool of the character stated which will effectively remove the solids which have been plugging or obstructing the perforations in the pipe or screen.

A feature of my invention resides in a means of passing clean wash Huid through the screen openings from the inside outwardly, thereafter passing the iluid downwardly through the annular space around the screen and then passing the washfluid through a perforated shoe below the screen and then carrying the Huid upwardly to the surface.

Another feature of my invention is to provide a tool of the character stated in which the wash fluid together with the entrained solids to be removed from the annular Aspace are pumped to the surface by the washing tool itself, thus reducing hydrostatic pressure on the formation and without passing the wash uid back through any of the screen openings. The wash fluid returns through provided outlet ports which are arranged below the perforated pipe or screen. f

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

Figure I is a fragmentary longitudinal sectional View of the lower portion of my washing tool.

Figure 2 is a fragmentary longitudinal sectional view of the upper portion of my washing tool.

Figure 3 is a fragmentary longitudinal sectional View of a slightly modied form of the upper portion of my washing tool.

Referring more particularly to the drawing, the numeral 1 indicates the usual casing which is set within the bore of the oil well. A perforated pipe or screen 2 is positioned below the casing 1 and is suitably cemented or packed oil:` as at 2', all of which is usual and well known in the art. The screen 2 is positioned within the producing formation of the oil well and an annular space Hatent --S'f 3 surrounds the screen 2, this annular space permitting oil to accumulate and then ilow through the holes or perforations of screen 2. A woven screen 2 may surround the pipe screen 2 for the purpose of preventing intrusion of coarse sand, rocks, etc. This wire screen wrapping is usual in the art. A plain or unperforated portion 4 of the screen 2 projects below this screen and is also positioned within the annular space 3 of the bore of the oil well. A `drill pipe or tubing 5 is run into the oil well and this pipe or tubing is coupled to the wash tool 6 in the following manner: ln the form of my invention shown in Figures 1 and 2 a pump barrel 7 forms the upper portion of the tool 6 and tube 8 extends downwardly from the bottom of the pump barrel 7. The purpose of this tube will be further described. A tubular pump rod 9 is coupled to the drill -pipe or tubing 5 and is provided with a piston 10 which may be reciprocated within the pump barrel 7 by reciprocating tubing 5 at the surface, thus providing a pumping action at the bottom of the well. The tube 8 has a packer 11 mounted thereon which engages the casing 1 at a point above the screen 2. Intake ports or holes 12 in the tube 8 above the packer 11 permit fluid to flow inwardly into the tube 8 from the casing 1. This fluid is either pumped or gravitated into the casing from the surface. At the lower end of the tube 8 I provide a pair of spaced packers 13a-14, one packer being faced upwardly and the other downwardly so that iluid will be confined between the packers. The tube 3 is provided with a number of holes 15 between the packers 13-14 through which fluid under pressure can pass outwardly for the purpose of cleaning or washing the holes or perforations 16 in the screen 2. A return pipe or conduit 17 extends into the bottom of the tube 8 through the packing 18, thus the return conduit 17 can move vertically within the tube or the tube can be moved relative to the conduit as will be subsequently described. A retainer packer 19 of any usual 'and well known type as shown in Patent No. 2,073,107, Figures 4 and 5 is' mounted within the portion 4 of the screen 2 substantially as shown. This packer may be of any type which will pack off with the conduit 17 and also permit the conduit to be latched thereto. This retainer packer 19 includes a ring packing 19 which bears against the pipe 4. The retainer 19 is provided with segmental or latched threads 20 and the conduit 17 is provided with matching threads 21 so that the conduit can be releasably attached to the retainer packer 19. The conduit 17 can be rotated to engage the threads Ztl-21, since the conduit is frictionally coupled to the tube by means of the packing v,18 which engages both lthe tube and the conduit. The tube 8, in turn, is attached to the drill pipe 5 and, therefore, the tube 8 can be rotated from the surface in the usual and well known manner employed in the drilling of a well. The conduit 17 is also provided with a ring seat 22 which rests on and seals at the upper end of the packer 19. When the threads 21 are engaged the seat 22 prevents fluid from owing downwardly into the retainer 19. Packing rings 23.011 the conduit 17 engage and seal against the inner wall of the packer 19. The retainer packer 19 is always in position during the producing operation of the well. However, if desired, a less expensive type of retainer packer could be employed, that is, it could be made of less expensive materials if the retainer 19 were removed. In any event, a suitable retainer packer 19 would always be in position in the well. A perforated shoe 24 on the lower end of the conduit 17 projects below the packer 19 and thus receives the flow from the annulus 3 permitting the wash fluid to pass upwardly through the conduit and thence to the surface. A packer 25 on the upper end of the conduit 17 seals oil against the wall of the tube 8 above the ports 12 so that the return uid can move 3 above this packer 25 and thence upwardly through the tube 8 and into the pump portion of the rod 9 and eventually to the surface through the driil pipe or tubing A check valve 25 may be provided on the upper end of the conduit 17 to prevent downward How of fiuid.

in Figure 3 I have eliminated the pump barrel 7 and the tube 3 is connected directly to the drill pipe or'tubing 5 substantially as shown. 'y

The pump barrel7 as shown'inrFigures land 2 may be Vemployed for the purpose of reducing pressures in 'thcVV tube 3 and if Ythis pump barrel-is thus used, i.e., if thc drill pipeor tube 5 is reciprocated to actuate the piston it?, then the pump barrel.7 may be held stationary within the casing 1 by the siips Z6 which are set by releasing the spring fingers 27 mounted on the outside of the barrel 7. This construction of the slips 26 and Vthernetlnzwi of setting them is usual and well known in the art as disclosed in one form in Patent No. 1,514,585.

Reciprocation of theV piston lb will create a reduced pres- .sure in lthe tube Stand the upward how of fluid in the pipe 1 will reduce the static pressure in that pipe. A

i ball check 9 is provided in the bottom of the rod 9' to prevent back flow o f fluid from the tubular rod 9.

In operation The retainer 19 hasbeen set in the lower end 4 of the l duit f7 is now coupled to the retainer' by the threads.

2l and the seat vZZ-en'gages thetop of the retainer as shown and seals off at this point. The packing cups .QJ- M are now positioned within the screen 2. By

. V4 Y the washing cups 1S and the washing operation as described.

Having described my invention, I claim: l. in an oil well including-a casing, a perforated pipe section at the lower end of the casing, said oil Well having an annular space around the perforated pipe and extendpacking means, a tube extending over the conduit and "Outlet holes lil are provided in the upper part of' the l Ybarrel 7 to allow iiuid to iiow upwardly in the pipe raising-the drill pipe or tubing 5 it is possible to raise the tube 8 upon which the cups 13,-14 are mounted to i moveV these cups over all of the perforations in the screen K 2. Thus it is possible to move these cups from the bottom of the-'top of the perforated or Vscreen area 2. The

jerticaliy since it hangs freely inthe well. pressureris introduced at `the surface` and moves downwardly in the casing l, passing through the Vports i2, thence downwardly in the tube 8 and out through the lholes 15 where'it passes through the `perforations 16 to lean them. Any'solid material which is obstructing the .holes X6 will be 'carried downwardly in the annulus 3 and. thence through the p'erforations in the shoe 24 and returns upwardly through theconduit 17 and the pipe A5v to the surface. Thus the return huid with its entrained Y V solids `does not return throughV the p'erforations 16v-'which are to be cleaned'but moves tothe bottom of the bored hole and returns to the surface l'through a'separate path, tuus eliminating the possibility of re-clogging or obstructpasses the check valve 25' and then moves into the tube S and into the pump barrel 7. While it is not essential to the operation-ofthe tool, it is possible to reciprocate the pistonli) Ywhile the perforations are being cleaned. v This reciprocationof the` piston will somewhat assist the Y' upward flowro'f fluid past the check valve 9, and it will also somewhat reduceV the static pressure in the pipe 1,'

ving the perforations in the piperor screen 2. The returning liuidwhen it moves upwardlythrough the conduit 1'7 if this should be desirable. Itis to be understood that p the slipsgd which Vengage the pipe 1- can always be moved f f upwardly; the slant of the teeth of the slips permits this. V Consequently, before the slips are ever set the tube S is Y V`lowered. to the bottom of the screen portion of the pipe auf] thereafter is lifted gradually from the bottom to the top of that screen. upwardly even though the slips 26 are set the tube 8 can then` always be moved upwardly which carries with it Since the barrel 7 can be'movedV spaced'the'refrom and reciprocable .withrelation to the conduit, another packer on said tube engaging the casing, said tube having ports vtherein above'the last named packer, a packer on the conduit fitting in said tube above said ports, a pair of spaced packers on the tube adjacent the lower end thereof, said spaced packers engaging the perforated pipe, said tube having outlet' holes therein positioned between said -pair ofspaced packers, and a perforated shoe on the lower end Yof saidA conduit, said Y an annular space around the'perforated pipe andv extend-A ing to the bottom of said perforated pipe, a clean out tool comprising a packing means mounted in said perforated pipe section and below the perforations thereof, a conduit extending vertically through said packing means, means releasably coupling Vsaid conduit to 4said packing means, a tube extending over the conduit and spaced therefrom and reciprocable with relation to the conduit, another packer on said tube engaging the casing, said` tube having ports therein above the last named packer, a packer on the conduit tting in said tube above said ports, a pair of spaced packers -on the tube adjacent the lower-end thereof, said spaced packers engaging .the perforated pipe, said tube having outlet holes Vtherein positioned between said pair of spaced packers, and a' `perforated shoe on the lower end of said conduit, said shoe being positioned below-the packing rneans to receive fluid from the annular space, av pump barrel positioned above said tube and communicating therewith, a tubular pump rod extending into the-pump barrel, and a piston on said pump rod withinsaid pump barrel.

3. In an-oil well including a casing, a perforated pipe Ysection fatthe lowere'nd of the casing, saidoilwell havingan annular` space around the l"perforated pipe .and

extending to the bottom of `said perforated pipe, a clean out tool comprising a packing means mounted in said perforated pipe section and below Vthe perforations thereof,'a vertical conduit, a ring s eaton the conduit, seating onV the Vpackingfrneansfmeans releasably ,couplingl said Vconduit to said packing means, at tube extending over the condui't'and spaced therefrom and'reciprocablev with relation to the conduit, ,a packer on thev tube engaging the casing, said tube having ports therein above said packer,

a packer on the Vconduit'iitting in said tube V'above said ports, apair of spaced packers on the'tube'fadjacent the lower end thereof,tsaid spaced packers engaging the perforatedl pipe, said tube-having outlet holes therein positionedbetween said Vlast named spacedV packers, and a section at the lower end of the casing, said oil well having an annular space around the perforated pipe and ex-Y tending to the bottom of said perforated pipe, a cleanV out tool comprising` a packing means mountedin said perforated pipeV sectionand below the perforations thereof, a vertical conduit, a ring Vseat on the conduit, seating on the packing means, means releasably coupling said.v conduit to saidpacking means, a tube extending over the conduit and reciprocable with relation to the conduit and spaced therefrom, a packer on the tube engaging the casing, said tube having ports therein above said packer, a packer on the conduit fitting in said tube above said ports, a pair of spaced packers on the tube adjacent the lower end thereof, said spaced packers engaging the perforated pipe, said tube having outlet holes therein positioned between said last named spaced packers, and a perforated shoe on the lower end of said conduit, said shoe being positioned below said packing means to receive fluid from the annular space, a pump barrel positioned above said tube and communicating therewith, a tubular pump rod extending into the pump barrel, and a piston on said pump rod within said pump barrel.

5. In an oil well including a casing, a perforated pipe section at the lower end of the casing, said oil well having an annular space around the perforated pipe and extending to the bottom of said perforated pipe, a clean out tool comprising a retainer packer mounted in the perforated pipe section and below the perforations thereof, a conduit extending vertically through the retainer packer, latch means on the retainer packer engaging the conduit to releasably secure said conduit in the retainer packer, a tube extending over the conduit and space therefrom and reciprocable with relation to the conduit, a packing in the tube engaging the conduit, a packer on the tube engaging the casing, said tube having ports therein above said last named packer, a packer on the upper end of said conduit fitting in said tube and above said ports, a pair of spaced packers on the lower end of said tube, vsaid spaced packers engaging the perforated pipe, said tube having outlet holes therein positioned between said spaced packers and a perforated shoe on the lower end of said conduit, said shoe being positioned below the retainer packer to receive fluid from the annular space.

6. In an oil well including a casing, a perforated pipe section at the lower end of the casing, said oil well having an annular space around the perforated pipe and extending to the bottom of said perforated pipe, a clean out tool comprising a retainer packer mounted in the perforated pipe section and below the perforations thereof, a conduit extending vertically through the retainer packer, latch means on the retainer packer engaging the conduit to releasably secure said conduit in the retainer packer, a tube extending over the conduit and spaced therefrom and reciprocable with relation to the conduit, a packing in the tube engaging the conduit, a packer on the tube engaging the casing, said tube having ports therein above said last named packer, a packer on the upper end of said conduit fitting in said tube and above said ports, a pair of spaced packers on the lower end of said tube, said spaced packers engaging the perforated pipe, said tube having outlet holes therein positioned between said spaced packers and a perforated shoe on the lower end of said conduit, said shoe being positioned below the retainer packer to receive fluid from the annular space, a pump barrel positioned above said tube and communicating therewith, a tubular pump rod extending into the pump barrel, and a piston on said pump rod within said pump barrel.

7. In an oil Well including a casing, a perforated pipe section at the lower end of the casing, said oil well having an annular space around the perforated pipe and extending to the bottom of said perforated pipe, a clean out tool comprising a packing means mounted in said perforated pipe section and below the perforations thereof, a conduit extending vertically through said packing means, means releasably coupling said conduit to said packing means, a tube extending over the conduit and spaced therefrom and reciprocable with relation to the conduit, another packer on said tube engaging the casing, said tube having ports therein above the last named packer, a packer on the conduit fitting in said tube above said ports, a pair of spaced packers on the tube adjacent the lower end thereof, said spaced packers engaging the perforated pipe, said tube having outlet holes therein positioned between said pair of spaced packers, and a perforated shoe on the lower end of said conduit, said shoe being positioned below the packing means to receive fluid from the annular space, a pump barrel positioned above said tube and communicating therewith, a tubular pump rod extending into the pump barrel, a piston on said pump rod within said pump barrel, and casing engaging slips on the outside of said pump barrel.

8. In an oil well including a casing, a perforated pipe section at the lower end of the casing, said oil well having an annular space around the perforated pipe and extending to the bottom of said perforated pipe, a clean out tool comprising a retainer packer mounted in the perforated pipe section and below the perforations thereof, a conduit extending vertically through the retainer packer, latch means on the retainer packer engaging the conduit to releasably secure said conduit in the retainer packer, a tube extending over the conduit and spaced therefrom and reciprocable with relation to the conduit, a packing in the tube engaging the conduit, a packer on the tube engaging the casing, said tube having ports therein above said last named packer, a packer on the upper end of said conduit tting in said tube and above said ports, a pair of spaced packers on the lower end of said tube, said spaced packers engaging the perforated pipe, said tube having outlet holes therein positioned between said spaced packers and a perforated shoe on the lower end of said conduit, said shoe being positioned below the retainer packer to receive iluid from the annular space, a pump barrel positioned above said tube and communicating therewith, a tubular pump rod extending into the pump barrel, a piston on said pump rod Awithin said pump barrel, and casing engaging slips on the outside of said pump barrel.

Kinney et al June 27, 1950 Baker Apr. 20, 1954

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